This invention provides an improvement in the apparatus of U.S. Pat. Nos. 4,012,271 in manufacture of glass containers that are so covered or wrapped with a heat shrinkable thermoplastic, one example thereof being disclosed in U.S. Pat. No. 3,760,968, wherein the containers are conveyed in vertical upright position by a ware handling conveyor in single file past an assembly station of a sleeve making apparatus. The sleeves are formed on this apparatus or in the alternative they are fed axially from the apparatus to overlie and encircle a portion of the container during the initial assembly stage of the tube. The sleeve assembly apparatus may take the form of a rotary turret machine with the spaced mandrels holding the plastic sleeves. The turret and the container conveyor are operated in a registered and synchronized manner and when the sleeves and containers are united telescopically initially so that the former encircles the latter, the containers are in a continuous movement through an assembly station. One such machine is disclosed in U.S. Pat. No. 3,959,065. From the assembly station, the containers and sleeves move to a heat applying apparatus to shrink the plastic sleeve snugly over the container surface whereat it is assembled. This is usually and conveniently accomplished by conveying the ware and sleeve through a tunnel-like oven chamber.
In conveying the ware and sleeve from the assembly station to the heating apparatus, as in the example just mentioned, there is a need to assure that the sleeve maintains itself in place on the container. Should the sleeve slip from its place or fall partly or totally from the container, the subsequent heating will shrink the sleeve where it happens to be at the time it arrives in the oven chamber. Therefore, to avoid off-ware and possible fouling of the equipment, it is important to assure the sleeve is kept in its assembled position up to and at the time of heat shrinking.
To do this, various means have been devised. One of these has been a use of underlying wire or rod running from the assembly machine or its assembly station to the oven. Another is the means devised in the aforementioned U.S. Pat. No. 3,959,065, wherein the sleeve and container at the point of telescopical assembly pass a narrow heater which in effect partially shrinks a band region of the plastic sleeve and attaches the sleeve to the bottle thereby holding it in place until final total heat shrinking is completed. Still another form of device used to assure this positioning of the sleeve is disclosed in the aforementioned U.S. Pat. No. 4,012,271 wherein an underlying bar extends from adjacent the assembly machine into the oven chamber and obviates the sleeve slipping axially on the container before shrinking.